The spring should have a greater displacement .
Greater spring constant = the more difficult it is to stretch a spring , due to stiffness.
a) 0.26 h
b) 71.4 km
Explanation:
a)
In order to solve the problem, we have to know what is the final velocity of the car.
Here, we assume that the final velocity reached by the car is

Therefore, we can find the time taken by the car to reach this velocity by using the suvat equation:

where:
u = 250 km/h is the initial velocity
is the acceleration of the car
v = 300 km/h is the final velocity
t is the time
Solving for t, we find:

b)
In order to find the distance covered by the car, we can use the following suvat equation:

where:
s is the distance covered
u is the initial velocity
a is the acceleration
t is the time
For the car in this problem, we have:
u = 250 km/h
t = 0.26 h (calculated in part a)

Therefore, the distance covered is

Since the outer plumage of the penguin can resist the flow of heat in the cold antarctic air they might gain a little of this heat to keep them warm by thermal convection.
<u>Explanation:</u>
- Convection is the circular movement that happens when hot air/liquid moves with molecules that were fast, making it less dense rises while the cold air/liquid drops down.
- Also, they follow the technique of standing together always in a group which further helps them to decrease the loss of heat between them.
- The plumage of penguin provides 80 percent of total insulation and is highly resistant to wind penetration.