Answer:
Choices A, B, and C are correct.
Explanation:
Let us look at each of the choices one by one:
A. It is a vector
Yes. Velocity is a vector, or it's a speed with direction.
B. It is the change in displacement divided by the change in time.
Yes. The velocity can be written as

where
is the displacement—a vector quantity.
C. It can be measured in meters per second.
Yes. The units of velocity are m/s, but also with a unit vector indicating the direction.
D. It is the slope of the acceleration vs. time graph.
Nope. The velocity is the slope of displacement vs. time graph.
Hence, only choices A, B, and C are correct.
Answer:
The total energy of the composite system is 7.8 J.
Explanation:
Given that,
Height = 0.15 m
Radius of circular arc = 0.27 m
Suppose, the entire track is friction less. a bullet with a m₁ = 30 g mass is fired horizontally into a block of wood with m₂ = 5.29 kg mass. the acceleration of gravity is 9.8 m/s.
Calculate the total energy of the composite system at any time after the collision.
We need to calculate the total energy of the composite system
Total energy of the system at any time = Potential energy of the system at the stopping point


Put the value in to the formula


Hence, The total energy of the composite system is 7.8 J.
The answer is C. 35m/s because there is no direction