Answer:
Time taken by the car = 6 seconds.
Explanation:
Given:
Case 1:
Initial velocity of the car, = 0
Final velocity of the car, = 30 m/s
Time taken by the car, = 12 sec
Case 2:
Initial velocity of the car, = 0
Final velocity of the car, = 15 m/s
Solution:
Lets find the acceleration in first case:
⇒ acceleration (a) = (final velocity - initial velocity) / time
⇒
⇒
⇒
⇒
Using this acceleration value we can find the time taken in case 2:
⇒ time taken (t2) = (final velocity - initial velocity) / acceleration
⇒
⇒
⇒
⇒
So time taken by the car to go from rest to 15 m/s is 6 seconds.
Answer:
The total net force is 17N in total.
Hope this helps :)
I think the question when stated clearly is: What factors does the coefficient of volume expansions depends on? I think that is volume expansion because of the word cubic. In physics, some materials expand in length and in volume, when temperature changes occur. Each kind of material has their empirical values of coefficient of volume expansion in units of m³/°C. So, the obvious factor here is temperature. Generally, as the temperature increases, the volume expands because the molecules move more rapidly occupying more space. For gases, the factor of pressure is also important. But for incompressible objects like solids and liquids, it does not depend on pressure effects anymore.
Answer:
1.53 s
Explanation:
Initially vertical component of velocity of the ball, uy = 7.5 m/s
Net displacement is vertical direction is zero, Δy =0
Use second equation of motion:
Δy = uy t + 0.5 a t²
Here, acceleration a = -g (g =9.8 m/s²)
Substitute all the values and solve for g
0 = 7.5 t -0.5 (9.8)t²
7.5 t = 4.9 t²
t = 1.53 s