Answer:
HENCE (3) IS ANSWER
Explanation:
α =ΔL/(LO×Δ T) or ΔL= α(LO×Δ T)
HERE ΔL IS CHANGE IN LENGTH, Lo is original length , α is coefficient of linear expansion , Δ T is change in temperature
α= 11 x 10 ^-6/°C , Δ T = 19-20 = -1°C
hence
ΔL= 11 x 10 ^-6×10×-1
= - 11×10^-5
MINUS SIGN SHOWS SHORTER
HENCE (3) IS ANSWER
Answer:
0.45 m/s in the negative x-direction
Explanation:
From the law of conservation of momentum, the sum of initial momentum equals the sum of final momentum
Momentum, p=mv where m is the mass and v is the velocity
where is the common velocity, and are velocities of magnet moving in positive x-direction and magnet moving in negative x-direction respectively, and are masses of magnet moving in positive x-direction and magnet moving in negative x-direction respectively.
Substituting 125 g for and 85 g for , 7.33 m/s , -11.9 m/s for then
Therefore, the velocity of single unit is 0.45 m/s in the negative x-direction
For this case, the first thing we are going to do is define a reference system.
We define the vertical axis of the reference system, pointing upwards.
Therefore, doing summation of forces in vertical direction we have:
Then, since we want the net force to be equal to zero, then:
From here, we clear the force that we must apply on the object:
The positive sign means that the force points upwards.
Answer:
to create a net force of zero on the object you must apply:
33 Newton upwards.