Answer:
t=0.42s
Explanation:
Here you have an inelastic collision. By the conservation of the momentum you have:
m1: mass of the bullet
m2: wooden block mass
v1: velocity of the bullet
v2: velocity of the wooden block
v: velocity of bullet and wooden block after the collision.
By noticing that after the collision, both objects reach the same height from where the wooden block was dropped, you can assume that v is equal to the negative of v2. In other words:
Where you assumed that the negative direction is upward. By replacing and doing v2 the subject of the formula you get:
Now, with this information you can use the equation for the final speed of an accelerated motion and doing t the subject of the formula. IN other words:
hence, the time is t=0.42 s
Answer:
The mass will accelerate. Balanced Forces: When forces are in balance, acceleration is zero. Velocity is constant and there is no net or unbalanced force. A plane will fly at constant velocity if the acceleration is zero.
Explanation:
Answer:
29.7 m/s fast, velocity is 29.7 m/s
Explanation:
Applying,
v² = u²+2gs...................... Equation 1
Where v = final velocity, u = initial velocity, g = acceleration due to gravity, s = distance.
Given: u = 0 m/s (dropped from height), s = 45 m
Constant: g = 9.8 m/s²
Substitute these values into equation 1
v² = 0²+2×9.8×45
v² = 882
v = √(882)
v = 29.7 m/s.
Hence the stone will be moving 29.7 m/s fast and the velocity is also 29.7 m/s
Answer = 31.5J (rounded to 1dp)
The question wants to find the work done, where work done can be calculated in the equation:
Work done = Force x Distance
The force is not given in the question, however they give the acceleration and mass, so you can calculate the force using Newton's second law:
Force = Mass x Acceleration
First, calculate the force. The mass is 45kg for the 3 boxes and the acceleration is 12.3m/s^2.
Force = 45 x 12.3
Force = 553.5N
Now that you have the force (553.5N) and distance (57cm), substitute those values into the equation for work done.
Make sure to convert the 57cm into metres (into SI units), otherwise the answer would be wrong.
57cm = 0.057m
Work done = Force x Distance
Work done = 553.5 x 0.057
Work done = 31.5J (rounded to 1dp)