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
Answer:
Magnitude = 14 metres
Direction = eastward.
Explanation:
A cross-country skier moves 36 meters eastward, then 44meters westward, and finally 22 meters eastward.
Whats the Magnitude and Direction?
The magnitude and direction will be the displacement of the cross country skier.
Let the east ward be positive and the west ward be negative.
Since the skier moves 36 meters eastward, then 44meters westward, and finally 22 meters eastward. Then, that will be:
36 - 44 + 22 = 14
Since the answer is positive, the magnitude is 14 and the direction is east ward.
Potential equals kenecric at the bottom so potential would also increas
Answer: a) 3.85 days
b) 10.54 days
Explanation:-
Expression for rate law for first order kinetics is given by:

where,
k = rate constant = ?
t = time taken for decomposition = 3 days
a = let initial amount of the reactant = 100 g
a - x = amount left after decay process = 
First we have to calculate the rate constant, we use the formula :
Now put all the given values in above equation, we get


a) Half-life of radon-222:


Thus half-life of radon-222 is 3.85 days.
b) Time taken for the sample to decay to 15% of its original amount:
where,
k = rate constant = 
t = time taken for decomposition = ?
a = let initial amount of the reactant = 100 g
a - x = amount left after decay process = 


Thus it will take 10.54 days for the sample to decay to 15% of its original amount.