Answer:
A)F
B)F
C)T
Explanation:
A)
This is not always true that the product of the two vector's always non-negative .It may be positive or negative.
That is why this statement is false.
B)
The unit vectors in three perpendicular direction is i ,j and k.
We know that for unit vectors
i.i=j.j=k.k= 1
i .j= j.k=k.i=0
Therefore only parallel component of the force will contribute in the integral part instead of perpendicular component of the force.
That is why this statement is false.
C)
This statement is True.
A)F
B)F
C)T
Answer:
Explanation:
u = 150 m/s
R = 800 m
The formula for the horizontal range is

where, θ is angle of projection.

Sin2θ = 0.348
2θ = 20.4°
θ = 10.2°
The range is same for the complementary angles.
So, the other angle is 90 - 10.2 = 79.8°
Answer: Work done = 153.125Joules, Work done = 0.003Nm
Explanation:
Kinetic energy of a body is the energy possessed by a body by virtue of its motion.
Mathematically,
K.E = 1/2MV²
Where;
M = mass of the body = 2.5g = 0.0025kg
V = velocity of the body = 350m/s
Substituting this values in the formula, we have;
K.E = 1/2× 0.0025×350²
K.E = 153.125Joules
Work done is the force applied to body to cause it to move through a distance.
Work = Force × distance
Force = ma = 0.0025 × 10
Force = 0.025N
Distance = 12cm = 0.12m
Work = 0.025×0.12
Work = 0.003Nm
work done by the tree in stopping the bullet is 0.003N
I believe the answer is a