Gamma rays ..........................
B. False
Endothermic reactions absorb heat.
I think the answer is discovery.
Answer:
-27.3 m/s
Explanation:
Given:
y₀ = 38 m
y = 0 m
v₀ = 0 m/s
a = -9.8 m/s²
Find: v
v² = v₀² + 2a (y − y₀)
v² = (0 m/s)² + 2 (-9.8 m/s²) (0 m − 38 m)
v = -27.3 m/s
Or, you can solve with energy.
PE = KE
mgh = ½ mv²
v² = 2gh
v = -27.3 m/s
The forces on the y axis are:
N-mgcos(60)=0 , wich becomes
N=mgcos(60)
Rember that the friction force is always contrary to the motion of an object and its formula is f=μ * N
The forces in the x axis are:
-f + mgsin(60)= m * a
-μ*mgcos(60) + mgsin(60)=m*a ,
μ = ( m*a - mgf=μ[sin(60) )/ ( mgcos(90) )
