Answer:
Constant speed: yes
Constant velocity: no
Explanation:
Let's remind the definition of speed and velocity:
- Speed is a scalar quantity, which is equal to the ratio between the distance covered (regardless of the direction) and the time taken:
- Velocity is a vector quantity, so it has both a magnitude and a direction. The magnitude is equal to the rate between the displacement of the object and the time taken, while the direction is the same as the displacement.
In this problem, we notice that:
- The speed of the car remains constant, as it is 90 km/h
- However, its direction of motion changes while the car travels round the corner: this means that the direction of the velocity is also changing, therefore velocity is not constant.
Answer:
A star with 15 solar masses is too big to be a main-sequence star.
Answer:
Total height (s) = 176.4 m
Explanation:
Given:
Initial velocity (u) = 0 m/s
Time taken (t) = 6 sec
Acceleration due to gravity = 9.8 m/s²
Find:
Total height (s)
Computation:
s = ut + [1/2]gt²
s = (0)(6) + [1/2][9.8][6²]
s = 176.4 m
Total height (s) = 176.4 m
The same braking force does work on these objects to slow them down. The work done is equal to their change in kinetic energy:
FΔx = 0.5mv²
F = force, Δx = distance traveled, m = mass, v = speed
Isolate Δx:
Δx = 0.5mv²/F
Calculate Δx for each object.
Object 1: m = 4.0kg, v = 2.0m/s
Δx = 0.5(4.0)(2.0)²/F = 8/F
Object 2: m = 1.0kg, v = 4.0m/s
Δx = 0.5(1.0)(4.0)²/F = 8/F
The two objects travel the same distance before stopping.
Death would happen, hope this helped
