The diagram shows a person using a piece of gym equipment to lift weights.

which best describes the body in terms of simple machines?

a. the knees are inclined planes, and the lower legs hold the loads. the ankles are the fulcrums.

b. the lower legs are inclined planes, and the knees hold the loads. the ankles are the fulcrums.

c. the lower legs are levers, and the knees are fulcrums. the ankles hold the loads.

d. the knees are levers, and the lower legs are fulcrums. the ankles hold the loads.

C. The lower legs are levers, and the knees are fulcrums. The ankles hold the loads.

Explanation:

As we know that while the person is doing exercise the weight is hold by the ankles as it is placed there.

Now the lower legs are bend while doing the exercise so we can say that lower legs are acting like lever which can rotate about one end and at the other end it is holding the weight

Now the knees are acting like fulcrum here because they are supporting the lower legs in such a way that they can rotate about its one end connected to knees

so correct answer will be

C. The lower legs are levers, and the knees are fulcrums. The ankles hold the loads.

the minimum constant speed at which she can catch the train is 2.7 m/s

given:

acceleration = 0.6

time = 4.5 s

to find:

velocity = ?

formula used:

from 1st kinematic equation we get,

v = u + at

u = initial speed of train = 0 m/s

v = final speed of the train

a = acceleration of the train

t = time

solution:

from 1st kinematic equation we get,

v = u + at

u = initial speed of train = 0 m/s

v = final speed of the train

a = acceleration of the train

t = time

v = 0 + (0.6 × 4.5)

v = 2.7 m/s

the minimum constant speed at which she can catch the train is 2.7 m/s