[填空题]
A jet aircraft is accelerating u hj3qvjifw+wme 9+(/ 7qjpmb5j 1f9rat 3.5 $\mathrm{~m} / \mathrm{s}^{2}$ at an angle of 45$^{\circ} $ above the horizontal. What is the total force that the cockpit seat exerts on the 75$-\mathrm{kg} $ pilot? N $^{\circ} $
