Q: A ball is thrown horizontally from the top of a $$45\ \mathrm{m}$$ high cliff with a speed of $$10\ \mathrm{m/s}. $$How far from the base of the cliff does the ball land? (Neglect air resistance, $$g = 9.8\ \mathrm{m/s^2$})$$

$$10\sqrt{\dfrac{2 \times 45}{9.8}}\ \mathrm{m}$$

Question 1

A car accelerates uniformly from rest to a speed of $$20\ \mathrm{m/s} in$$ $$10\ \mathrm{s}. $$What is the magnitude of its acceleration?

Accepted Answer

$$1.0\ \mathrm{m/s^2$}$$

Question 2

A ball is thrown horizontally from the top of a $$45\ \mathrm{m}$$ high cliff with a speed of $$10\ \mathrm{m/s}. $$How far from the base of the cliff does the ball land? (Neglect air resistance, $$g = 9.8\ \mathrm{m/s^2$})$$

Accepted Answer

$$10\sqrt{\dfrac{2 	imes 45}{9.8}}\ \mathrm{m}$$

Question 3

A $$5\ \mathrm{kg}$$ box is pulled across a horizontal surface with a constant force of $$20\ \mathrm{N}. If $$the coefficient of kinetic friction is $$0.2$$, what is the acceleration of the box? ($$g = 9.8\ \mathrm{m/s^2$})$$

Accepted Answer

$$0.8\ \mathrm{m/s^2$}$$

Question 4

A $$0.15\ \mathrm{kg}$$ baseball moving at $$40\ \mathrm{m/s} is $$hit by a bat and reverses direction, leaving the bat at $$60\ \mathrm{m/s}. $$What is the magnitude of the impulse delivered to the ball?

Accepted Answer

$$15.0\ \mathrm{kg\cdot m/s}$$

Question 5

A $$2\ \mathrm{kg}$$ object is moving at $$3\ \mathrm{m/s}$$ east. It collides head-on and sticks to a $$1\ \mathrm{kg}$$ object moving at $$-2\ \mathrm{m/s} ($$west). What is the velocity of the combined mass after the collision?

Accepted Answer

$$1.33\ \mathrm{m/s}$$\ east

Question 6

A $$0.5\ \mathrm{kg}$$ mass is attached to a spring with a spring constant $$k = 200\ \mathrm{N/m}. $$What is the period of oscillation for this mass-spring system?

Accepted Answer

$$0.314\ \mathrm{s}$$

Question 7

A $$10\ \mathrm{kg}$$ object is lifted vertically at constant speed through a height of $$5\ \mathrm{m}. $$How much work is done by the lifting force? ($$g = 9.8\ \mathrm{m/s^2$})$$

Accepted Answer

$$490\ \mathrm{J}$$

Question 8

A $$2\ \mathrm{kg}$$ object moves in a circle of radius $$0.5\ \mathrm{m} at a $$constant speed of $$4\ \mathrm{m/s}. $$What is the magnitude of the centripetal force acting on the object?

Accepted Answer

$$32\ \mathrm{N}$$

Question 9

A $$0.2\ \mathrm{kg}$$ ball is attached to a $$0.5\ \mathrm{m}$$ string and swung in a horizontal circle at $$3\ \mathrm{m/s}. $$What is the angular velocity $$\omega of $$the ball?

Accepted Answer

$$12\ \mathrm{rad/s}$$

Question 10

A $$1.5\ \mathrm{kg}$$ block slides down a frictionless incline of height $$2.0\ \mathrm{m}. $$What is its speed at the bottom of the incline? ($$g = 9.8\ \mathrm{m/s^2$})$$

Accepted Answer

$$6.3\ \mathrm{m/s}$$

Question 11

A $$0.5\ \mathrm{kg}$$ ball moving at $$2\ \mathrm{m/s}$$ collides elastically with a stationary $$0.5\ \mathrm{kg}$$ ball. What is the velocity of the first ball after the collision?

Accepted Answer

$$-2\ \mathrm{m/s}$$

Question 12

A $$3\ \mathrm{kg}$$ object is rotating with an angular velocity of $$4\ \mathrm{rad/s}$$ about an axis $$2\ \mathrm{m}$$ from its center. What is its angular momentum?

Accepted Answer

$$24\ \mathrm{kg\cdot m^2$/s}$$

Question 13

A $$0.1\ \mathrm{kg}$$ mass oscillates on a spring with amplitude $$0.2\ \mathrm{m}$$ and period $$0.5\ \mathrm{s}. $$What is the maximum speed of the mass?

Accepted Answer

$$2.51\ \mathrm{m/s}$$

Question 14

A $$1.0\ \mathrm{kg}$$ block is submerged in water and experiences an upward buoyant force of $$9.8\ \mathrm{N}. $$What is the volume of the block? ($$g = 9.8\ \mathrm{m/s^2$}$$, $$\rho_{water} = 1000\ \mathrm{kg/m^3$})$$

Accepted Answer

$$0.001\ \mathrm{m^3$}$$

Question 15

A $$2.0\ \mathrm{kg}$$ object at $$300\ \mathrm{K}$$ absorbs $$1000\ \mathrm{J} of $$heat. If its specific heat is $$500\ \mathrm{J/(kg\cdot K)}$$, what is its final temperature?

Accepted Answer

$$305\ \mathrm{K}$$

Question 16

A $$0.3\ \mathrm{kg}$$ mass attached to a string is swung in a vertical circle of radius $$0.8\ \mathrm{m}. At $$the lowest point, its speed is $$5\ \mathrm{m/s}. $$What is the tension in the string at this point? ($$g = 9.8\ \mathrm{m/s^2$})$$

Accepted Answer

$$15.3\ \mathrm{N}$$

Question 17

A $$0.5\ \mathrm{kg}$$ block is pushed against a spring (spring constant $$k = 100\ \mathrm{N/m}) $$compressing it by $$0.2\ \mathrm{m}. $$When released, what is the speed of the block as it leaves the spring (on a frictionless surface)?

Accepted Answer

$$4.0\ \mathrm{m/s}$$

Question 18

A $$1.0\ \mathrm{kg}$$ object is dropped from rest from a height of $$20\ \mathrm{m}. $$What is its kinetic energy just before hitting the ground? ($$g = 9.8\ \mathrm{m/s^2$})$$

Accepted Answer

$$196\ \mathrm{J}$$

Question 19

A $$0.2\ \mathrm{kg}$$ mass oscillates on a spring with a maximum displacement of $$0.1\ \mathrm{m}. If $$the spring constant is $$50\ \mathrm{N/m}$$, what is the total mechanical energy of the system?

Accepted Answer

$$0.50\ \mathrm{J}$$

Question 20

A $$0.5\ \mathrm{kg}$$ object floats in water with $$0.4\ \mathrm{kg} of $$water displaced. What is the buoyant force acting on the object? ($$g = 9.8\ \mathrm{m/s^2$})$$

Accepted Answer

$$3.92\ \mathrm{N}$$

PHY 101 – College Physics I: Syllabus and Course Structure Overview

Guida di studio - Domande di pratica

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