Hubble time in cosmology means the estimated age of the universe and the best calculation for it is T=1/H, where H is the Hubble constant
a. We can calculate the amount of work by calculating the area under the graph.
first area (rectangular): 2.5 x 6 = 15
second area(trapezoid): 1/2 x (6+10) x 2.5 =20
total work done: 35 J
b. the force was first applied = 6 N
F = m.a
a = 6 : 3 = 2 m/s²
vf²=vi²+2as
vf²=6²+2.2.5
vf²=56
vf=7.5 m/s
Answer:
c.100 minutes
Explanation:
Total distance = 10 km
Runs for 1 km every 5 minutes
walks 1 km every 15 min
She alternates between walking and running so, Jessica will walk 5 km and run 5 Km
Time taken by Jessica for walking
: 5 km
Time taken to walk 1 km=5 minutes
Time taken to walk 5 km
=> 5 X 5
=>25 minutes
Time taken by Jessica for Running
: 5km
Time taken to run 1 km = 15 minutes
=> 5 X 15
=>75 minutes
Total time taken = Time taken by Jessica for walking + Time taken by Jessica for Running
=>25 minutes +75 minutes
=> 100 minutes
Explanation:
It is given that,
Mass of the tackler, m₁ = 120 kg
Velocity of tackler, u₁ = 3 m/s
Mass, m₂ = 91 kg
Velocity, u₂ = -7.5 m/s
We need to find the mutual velocity immediately the collision. It is the case of inelastic collision such that,
v = -1.5 m/s
Hence, their mutual velocity after the collision is 1.5 m/s and it is moving in the same direction as the halfback was moving initially. Hence, this is the required solution.
