Answer:
Explanation:
Person A's velocity relative to the train is 0. Therefore, the pitch of the horn will not change.
Explanation:
Graph A matches description 4 because the car is coming back.
Graph B matches description 3 because the speed of the car is decreasing.
Graph C matches the description 2 because the car is traveling at a constant rate.
Graph D matches the description 1 because the car is stopped.
Answer
Given,
Time to hear the clap = 14.4 s
speed of the light = 3 x 10⁸ m/s
Speed of sound = 343 m/s
a) distance where lightning strike
D = s x t
D = 14.4 x 343
D = 4939.2 m
b) No, we do not need to know the value of speed of light. Because we need to calculate the distance where we hear the sound. To calculate that we need to know the speed of sound.
Answer:
Random motion
Explanation:
If the boy throws the basketball forward while at a position on the skateboard, the motion of the ball will be a random motion since we are not told if the ball is moving on a straight line when thrown forward.
In this case, the boy will tend to move in the direction of the ball. Since the ball is moving in a random manner, the motion of the boy will also be a random motion.
A random motion is a motion of a body in a zig zag manner. It is also known as Brownian motion e.g motion of a buzzing mosquito, motion of a smoke coming out of a chimney etc.
Answer: 52%
Explanation:
1W = 1 J/s
motor input is 10000 J/s
Potential energy change
PE = 955(9.81)(25.0) = 234,213.75
power needed to change the PE in that time
P = 234,213.75/ 45 = 5,204.75 Watts
motor is 5204.75 / 10000 = 0.520475 or 52% efficient
