Which of the following represents a negative displacement
An object moving backward
A 5000kg truck and a 1000kg car are travelling at constant speeds and then collides. What is true about the Forces and acceleration on each?
5000kg truck exerts a greater force on the 1000kg car, but the acceleration will be same.
Students were tasked with dropping a 0.2 kg bag of marbles straight down into a 1.0 kg toy cart moving at 3.0 m/s. The students compare the velocity of the cart before and after the marbles are dropped.
toy cart
How did the addition of the bag of marbles affect the velocity of the cart?
The Cart's velocity stayed constant because the 0.20 kg bag was small when compared to the 1.0 kg mass of the cart.
A ball is dropped from a height of 20 meters. What is its velocity when it hits the ground?
19.8 m/s (rounded to one decimal place).
A 2 kg object is lifted 5 meters off the ground. How much work is done against gravity?
W = 2 kg × 9.8 m/s^2 × 5 m = 98
What is the SI unit for acceleration?
m/s^2
Kids were playing with balls which are of equal mass. They kicked them with different forces. Which one accelerated more?
Red ball – 10N
Blue ball – 3N
Yellow ball - 5N
Red ball since force and acceleration are directly related.
A layer of padding is added to car dashboards because it can reduce some injuries during a collision. How does the padded dashboard make people safer?
It decreases the impulse during the collision
A projectile is launched with an initial velocity of 30 m/s at an angle of 60 degrees above the horizontal. Determine the horizontal and vertical components of the initial velocity.
25.98 m/s (rounded to two decimal places).
A car accelerates from 0 to 30 m/s in 5 seconds. If the car's mass is 1000 kg, what is the average power exerted on the car during this acceleration?
P = 90,000 J / 5 s = 18,000
What is the average acceleration of an object that changes its velocity from 10 m/s to 30 m/s in 5 seconds?
4 m/s^2
Rank the magnitude of acceleration from least to greatest?
A B C D
D>C>B>A
Object A, with a mass of 5kg, is moving at a velocity of 3 m/s while Object B, with a mass of 3 kg is moving at a velocity of -5 m/s. Based on the calculations of their momentum, which of the following statements is correct?
The magnitude of the objects' momenta and direction are equal
An object is thrown vertically upward with an initial velocity of 25 m/s. How high does it go before falling back to its initial position?
31.89 m (rounded to two decimal places).
What happens to the total energy of a roller coaster as it goes down a steep hill?
The total energy of a roller coaster increases as it goes down a steep hill. The potential energy of the roller coaster is converted into kinetic energy due to its change in height. As the roller coaster goes down the hill, it gains speed and its kinetic energy increases.