1. The time for a radioactive sample to reduce to half of its original mass.
4. 10% of 232 is 23.2 times 6 equals 139.2
68.9 x6 equals 413.4
5. 0.37kg
6. 2000 years
7. 6.84 seconds
Answer:
physical sicence boilagiy sxcience and earth science
Explanation:
Explanation:
Given:
v₀ = 0 m/s
a = 9.8 m/s²
t = 4.7 s
Find: Δy
Δy = v₀ t + ½ at²
Δy = (0 m/s) (4.7 s) + ½ (9.8 m/s²) (4.7 s)²
Δy ≈ 110 m
Answer:
Pressure applied by the man= 285103.125
or 41.35 
Explanation:
Pressure is defined as the perpendicular force applied per unit area.
i.e. 
Now, 
where,
= mass of the body(man) = 93 kg
= acceleration due to gravity of Earth = 9.81 
covered is equal to the area of both stilts(a man generally stands on two feet)
therefore

and putting in the values, we get,

Now we need to convert to our required units:

(We can get the above result by individually converting kg to lb and meters to inches respectively)
Using the above relations we get,

When the ball starts its motion from the ground, its potential energy is zero, so all its mechanical energy is kinetic energy of the motion:

where m is the ball's mass and v its initial velocity, 20 m/s.
When the ball reaches its maximum height, h, its velocity is zero, so its mechanical energy is just gravitational potential energy:

for the law of conservation of energy, the initial mechanical energy must be equal to the final mechanical energy, so we have

From which we find the maximum height of the ball:

Therefore, the answer is
yes, the ball will reach the top of the tree.