Answer:
a) KA = 1.2 J
b) vB = 5.00 m/s
c) W = 6.30 J
Explanation:
m = 0.600 kg
vA = 2.00 m/s
KB = 7.50 J
a) KA = ?
b) vB = ?
c) W = ?
We can apply the folowing equations
K = 0.5*m*v²
and
W = ΔK = KB- KA
then
a) KA = 0.5*m*vA² = 0.5*(0.600 kg)*(2.00 m/s)²
⇒ KA = 1.2 J
b) KB = 0.5*m*vB² ⇒ vB = √(2*KB / m)
⇒ vB = √(2*7.50 J / 0.600 kg)
⇒ vB = 5.00 m/s
c) W = ΔK = KB- KA = (7.50 J) - (1.2 J)
⇒ W = 6.30 J
Answer:
A) 8π ft²/ft
B) 24π ft²/ft
C) 48π ft²/ft
Explanation:
Surface area of the spherical balloon is not clear here but it is supposed to be;
S = 4πr²
where:
r is the radius of the spherical balloon
So thus, the rate of change of the surface area of the spherical balloon by its radius will be:
dS/dr = 8πr
A) at r = 1ft;
dS/dr = 8 × π × 1
dS/dr = 8π ft²/ft
B) at r = 3 ft;
dS/dr = 8 × π × 3
dS/dr = 24π ft²/ft
C) at r = 6ft;
dS/dr = 8 × π × 6
dS/dr = 48π ft²/ft
Answer: 9 m
Explanation:
Work is said to be done when an unbalanced force causes displacement of the body.
Force is the product of mass (m) and acceleration (a).
Work = Force × Displacement
⇒W = F.s = ma.s
It is given that mass of the dresser is, m = 250 kg
work done, W = 126 J
Force acting on the dresser, F = 14 N
we need to find displacement, s
⇒126 J = 14 N × s
⇒ s = 126 J/ 14 N = 9 m
Hence, Laurie is able to move the dresser to about 9 m.
Answer:
The car evidently moved in the South-North direction.
Mașina se deplasa în mod evident în direcția Sud-Nord.
Explanation:
English Translation
At night, in a dark room, you notice on the wall opposite the window the movement of light spots from the headlights of a car in a south-north direction. In what direction did the car move?
Solution
Light rays fall obliquely on walls but move in the same direction as the car's direction of travel. And from the question, it is stated that the light rays move in the south-north direction, hence, the car in question, moved in the South-North direction too.
In Romanian/In limba romana
Razele de lumină cad oblic pe pereți, dar se mișcă în aceeași direcție ca direcția de deplasare a mașinii. Și din întrebare, se precizează că razele de lumină se deplasează în direcția sud-nord, prin urmare, mașina în cauză se deplasa și în direcția Sud-Nord.
Hope this Helps!!!
Sper că acest lucru vă ajută!!!
Refer to the diagram shown below.
The weight of the block is
W = (2.41 kg)*(9.8 m/s²) = 23.618 N
The kinetic coefficient of friction is
μ = 0.521
The normal reaction is
N = f cos(59.9°) = 0.5015f N
The frictional resistive force is
R = μN = 0.521*(0.5015f N) = 0.2613f N
For dynamic force balance,
f sin(59.9°) = W + R
0.8652f = 23.618 + 0.2613f
0.6039f = 23.618
f = 39.109 N
The block moves by 1.42 m.
The work done is
W = (f sin(59.9° N)*(1.42 m)
= 39.109*sin(59.9°)*1.42
= 48.05 J
Answer: 48.0 J (nearest tenth
