Answer:
176 min
Explanation:
456 g = .456 kg
Specific heat of ice s = 2093 J kg⁻¹
Heat required to raise the temperature by 25 degree
= mass x specific heat x rise in temperature.
= .456 x 2093 x 25
=23860 J
Heat required to melt the ice to make water at zero degree
= mass x latent heat
= .456 x 334 x 10³
=152304 J
Total heat required = 152304 + 23860 = 176164 J .
Time Required = Heat required / rate of supply of heat
= 176164 / 1000
176.16 min
Answer:
D. 48.985 N
Explanation:
Newton's second law states that:
which means that the net force acting on an object is equal to the product between the object's mass and its acceleration.
The equation of the forces for the briefcase in the elevator therefore is given by:
where
N is the normal reaction exerted on the briefcase
(mg) is the weight of the briefcase, with
m = 4.5 kg being its mass
g = 9.8 m/s^2 is the acceleration of gravity
a = 1.10 m/s^2 is the acceleration
Here we chose upward as positive direction.
Solving for N, we find the normal force:
So the closest answer is
D. 48.985 N
Answer: 2.37N
Explanation:
According to coulombs law which states that the force of attraction (F) between two charges (q1 and q2) is directly proportional to the product of their charges and inversely proportional to the square of the distance (r) between them. Mathematically,
F = kq1q2/r²
For the first two charges that are sitting 1.5 m apart with a force of 3 N between them, we have
3 = kq1q2/1.5²
3 = kq1q2/2.25
Kq1q2= 6.75... (1)
If the charges are now moved farther apart 2.25 m and one of the charges is increased by a factor of 4. The formula becomes
F2 = k(4q1)q2/2.25² (q1 has been increased by factor of 4)
k(4q1)q2 = 5.06F2 ... (2)
Dividing 2 by 1 we have
k(4q1)q2/kq1q2 = 5.06F2/3
4 = 5.06F2/3
5.06F2 = 12
F2= 12/5.06
F2 = 2.37N
Therefore the magnitude of the new force between the two charges is 2.37N
Friction is the force that acts on the opposite side of direction of force, thus it manages to decelerate an object, so it acts upward along the plane
Answer:
c : it wil be cut in half.
The pattern is formed on a distant screen so we can use the Fraunhofer difracction for a single slit. The formula of the width of the central bright spot is given by Δx = (2λz)/a, where λ is the wavelength and a is the width of the slit. So if the inicial width (a_1) is doubled (a_2= 2 x a_1),the width of the central spot will be cut in half Δx = (2λz)/a_2 = (2λz)/2xa_1 .
