Hey guys i have some questions about Physics. 1) The cart is initially at rest.
ID: 2135617 • Letter: H
Question
Hey guys i have some questions about Physics.
1) The cart is initially at rest. Force
F? is applied to the cart for time ? t, after which the car has speed v. Suppose the same force is applied for the same time to a second cart with twice the mass. Friction is negligible. Afterward, the second cart's speed will be
a) 2v
b) 1/2v
c) v
d) 4v
e) 1/4v
2) A ring, seen from above, is pulled on by three forces. The ring is not moving. How big is the force F?
a) 10costheta N
b) 20sintheta N
c) 10sintheta N
d) 20costheta N
e) 20 N
3) An astronaut takes her bathroom scales to the moon, where g = 1.6 m/s^2. On the moon, compared to at home on earth:
a) Her weight is the same, and her mass is the same
b) Her weight is less, and her mass is the same.
c) Her weight is the same, and her mass is less.
d) Her weight is zero, and her mass is the same.
e) Her weight is less, and her mass is less.
4) A box is being pulled to the right over a rough surface. T>
fk , so the box is speeding up. Suddenly the rope breaks. What happens? The box
a) Slows steadily until it stops.
b) Continues with the speed it had when the rope broke.
c) Stops immediately.
d) Keeps its speed for a short while, then slows and stops.
e) Continues speeding up for a short while, then slows and stops.
thanks beforehand
Explanation / Answer
1 b
2 insufficient data
3 b
4 a
Explanation :
1. F = ma
v = u+at
so ,
F = ma1
v1= a1t
v1 = F/m * t
v2 = F/2m * t
v2 = v/2 .
2. Insufficient data mass is not given .
3. weight = m * g
m= mass , g= acceleration due to gravity
so on eqrth g > moon g , and m remains the same as body content doesnt change
hence mass remain same weight decreases
4 . v= u+ at
till tension is there a is positive block will be speeding up but when its cut it suddenly changes its direction hence steadily decreasing due to frictional force and finally becomes zero