Q: A 1400 kg car slows from $$19\ \mathrm{m/s} to$$ $$16\ \mathrm{m/s}$$ over a $$25.0\ \mathrm{m}$$ stretch of sandy road. What is the net work done on the car?

$$-7.35 \times 10^4$\ \mathrm{J}$$

Question 1

Which of the following quantities has the same dimensions as acceleration?

Accepted Answer

$$\frac{v^2$}{r}$$

Question 2

A car is moving eastward and begins to slow down as it approaches a red light. Which of the following statements is correct about its acceleration?

Accepted Answer

The acceleration is directed westward.

Question 3

A particle moves in a circle at constant speed. Which of the following is true?

Accepted Answer

The particle has non-zero acceleration.

Question 4

If the speed of a car is halved, what happens to its kinetic energy?

Accepted Answer

It becomes one-fourth as much.

Question 5

A 1400 kg car slows from $$19\ \mathrm{m/s} to$$ $$16\ \mathrm{m/s}$$ over a $$25.0\ \mathrm{m}$$ stretch of sandy road. What is the net work done on the car?

Accepted Answer

$$-7.35 	imes 10^4$\ \mathrm{J}$$

Question 6

A block of mass $$m is $$suspended by a rope and is at rest. What is the tension $$T in $$the rope?

Accepted Answer

$$T = mg$$

Question 7

A $$2.0\ \mathrm{kg}$$ block slides down a frictionless incline of height $$5.0\ \mathrm{m}. $$What is its speed at the bottom?

Accepted Answer

$$\sqrt{2gh} = 9.9\ \mathrm{m/s}$$

Question 8

A $$5.0\ \mathrm{kg}$$ object is acted on by a net force of $$20\ \mathrm{N}. $$What is its acceleration?

Accepted Answer

$$4.0\ \mathrm{m/s^2$}$$

Question 9

A $$0.5\ \mathrm{kg}$$ ball is thrown straight up with an initial speed of $$10\ \mathrm{m/s}. $$What is the maximum height it reaches? (Neglect air resistance)

Accepted Answer

$$5.1\ \mathrm{m}$$

Question 10

A $$3.0\ \mathrm{kg}$$ block is pulled across a horizontal surface with a force of $$15\ \mathrm{N} at an $$angle of $$30^\circ$$ above the horizontal. If the coefficient of kinetic friction is $$0.2$$, what is the acceleration of the block?

Accepted Answer

$$3.1\ \mathrm{m/s^2$}$$

Question 11

A $$2.0\ \mathrm{kg}$$ object moves in a circle of radius $$0.5\ \mathrm{m} at a $$constant speed of $$4.0\ \mathrm{m/s}. $$What is the magnitude of the net force acting on the object?

Accepted Answer

$$64\ \mathrm{N}$$

Question 12

A $$1.5\ \mathrm{kg}$$ object is dropped from a height of $$20\ \mathrm{m}. $$What is its velocity just before hitting the ground? (Neglect air resistance)

Accepted Answer

$$20\ \mathrm{m/s}$$

Question 13

A $$10\ \mathrm{kg}$$ box is at rest on a horizontal surface. The coefficient of static friction is $$0.4. $$What is the minimum horizontal force required to start moving the box?

Accepted Answer

$$39.2\ \mathrm{N}$$

Question 14

A $$2.0\ \mathrm{kg}$$ object is moving at $$3.0\ \mathrm{m/s}. $$What is its kinetic energy?

Accepted Answer

$$9.0\ \mathrm{J}$$

Question 15

A $$0.2\ \mathrm{kg}$$ ball is thrown horizontally from a $$45\ \mathrm{m}$$ high cliff. How long does it take to reach the ground? (Neglect air resistance)

Accepted Answer

$$3.0\ \mathrm{s}$$

Question 16

A $$1.0\ \mathrm{kg}$$ object is moving with velocity $$\vec{v} = (3\hat{i} + 4\hat{j})\ \mathrm{m/s}. $$What is the magnitude of its momentum?

Accepted Answer

$$5.0\ \mathrm{kg\cdot m/s}$$

Question 17

A $$0.5\ \mathrm{kg}$$ object is moving at $$2.0\ \mathrm{m/s}$$ and collides elastically with a stationary $$0.5\ \mathrm{kg}$$ object. What is the velocity of the first object after the collision?

Accepted Answer

$$0\ \mathrm{m/s}$$

Question 18

A $$10\ \mathrm{kg}$$ mass is lifted vertically upward at constant speed by a rope. What is the work done by the tension in the rope when the mass is raised $$2.0\ \mathrm{m}$$?

Accepted Answer

$$196\ \mathrm{J}$$

Question 19

A $$1.0\ \mathrm{kg}$$ object is moving in the $$x-$$direction with a velocity of $$5.0\ \mathrm{m/s}. A $$constant force of $$2.0\ \mathrm{N}$$ acts in the $$x-$$direction for $$3.0\ \mathrm{s}. $$What is the final velocity of the object?

Accepted Answer

$$11.0\ \mathrm{m/s}$$

Physics 1: Core Concepts, Formulas, and Problem-Solving Strategies

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