Answer: a) 42Nm b) 8.4m/s
Explanation:
Impulse is defined as object change in momentum.
Since Force = mass × acceleration
F = ma
Acceleration is the rate of change in velocity.
F = m(v-u)/t
Cross multiply
Ft = m(v-u)
Since impulse = Ft
and Ft = m(v-u)... (1)
The object change in velocity (v-u) = Ft/m from eqn 1
Going to the question;
a) Impulse = Force (F) × time(t)
Given force = 14N and time = 3seconds
Impulse = 14×3
Impulse = 42Nm
b) The object change in velocity (v-u) = Ft/m where mass = 5kg
v-u = 14×3/5
Change in velocity = 42/5 = 8.4m/s
Answer:
The branch of physical science that deals with the relations between heat and other forms of energy (such as mechanical, electrical, or chemical energy), and, by extension, of the relationships between all forms of energy.
Answer:
See the answers below
Explanation:
We can solve both problems using vector sum.
a)
Let's assume the forces that help the diver dive as positive downward, and the forces that oppose upward, as negative
![F_{resultant}=100+30-85+900\\F_{resultant}=845[N]](https://tex.z-dn.net/?f=F_%7Bresultant%7D%3D100%2B30-85%2B900%5C%5CF_%7Bresultant%7D%3D845%5BN%5D)
The drag force is horizontal d this way in the horizontal direction we will only have the drag force that produces the water stream.
![F_{drag}=50[N]](https://tex.z-dn.net/?f=F_%7Bdrag%7D%3D50%5BN%5D)
b)
Let's assume the forces that propel the rocket upwards as positive and forces like the weight of the rocket and other elements as negative forces.
![F_{resultant}=960+7080-7700\\F_{resultant}=340 [kN]](https://tex.z-dn.net/?f=F_%7Bresultant%7D%3D960%2B7080-7700%5C%5CF_%7Bresultant%7D%3D340%20%5BkN%5D)
P=mv
pi =pf
(68x2.79)+(131x0) = 199v
v= 0.95 m/s
