Physical Science Midterm Review

These flashcards cover key concepts and calculations related to Newton's laws of motion, forces, acceleration, friction, speed, and velocity.

What are Newton's three laws of motion?

1. An object at rest stays at rest, and an object in motion stays in motion unless acted on by an unbalanced force. 2. Force equals mass times acceleration (F = ma). 3. For every action, there is an equal and opposite reaction.

What would be harder to accelerate, a 5 kg ball or a 1000 kg boulder?

A 1000 kg boulder, because it has more mass and requires more force to accelerate.

What is the acceleration of a 70 kg box experiencing a net force of 400 N?

The acceleration is 5.7 m/s².

What is the weight of a 50 kg object on Earth?

The weight is 490 N, calculated using W = mg (W = 50kg x 9.8 m/s²).

What is the net force acting on a 45 kg block pulled with an applied force of 300 N and experiencing a frictional force of 100 N?

The net force is 200 N.

What is the mass of a box that experiences a net force of 60 N and accelerates at 7 m/s²?

The mass of the box is 8.6 kg.

What is the required force for a rocket of mass 850 kg to accelerate at 15 m/s²?

The required force is 12,750 N.

What is static frictional force for a 4.5 kg block with a static friction coefficient of 0.90?

The maximum static frictional force is 39.7 N.

What is the force of friction on a 2.5 kg block with a coefficient of kinetic friction of 0.75?

The force of friction is 18.375 N.

If a block is pulled by a 15 N force and the friction force is 18.375 N, what is the net force acting on the block?

The net force is -3.375 N (indicating the block does not move).

What force does a soccer ball apply to a person's foot if the ball experiences a 2000 N force?

The soccer ball applies a 2000 N force to the person's foot.

What is the speed of a mass with a radius of 0.75 m and a period of revolution of 0.50 seconds?

The speed is 9.42 m/s.

How long does it take a 2000 kg car to make a lap around a track with a radius of 400 m and speed of 30 m/s?

The time taken is about 83.775 seconds.

Explain the difference between speed and velocity.

Speed is how fast an object moves (distance/time), without direction. Velocity is speed with a direction (displacement/time).

What is the acceleration equation?

The acceleration equation is a = (final velocity - initial velocity) / time.

What is the acceleration of a car that accelerates from rest to 26.8 m/s in 5.1 seconds?

The acceleration is 5.25 m/s².

How far does a sled travel in 10 seconds while accelerating from 6 m/s to 15 m/s?

The sled travels 105 meters.

If a ladybug walks 15 cm forward and 4 cm backward in 30 seconds, what is its average speed?

The average speed is 0.63 cm/s.

What is the average speed of an NFL wide receiver running 100 m in 5.5 seconds?

The average speed is 18.18 m/s.